Authors: Dr. C. Ascehle on behalf of the STAR Network Investigators

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Preoperative fluorouracil (FU)-based chemoradiation +/- weekly oxaliplatin in locally advanced rectal cancer. Pathologic response

analysis of the STAR (Studio Terapia Adiuvante Retto)-01 randomized phase III trial

Authors: Dr. C. Ascehle on behalf of the STAR Network InvestigatorsDate posted: ASCO Oral Presentation June 2009Reviewed by Dr. Christopher Booth

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RTreatment A:

50.4 Gy with 5-FU CIV 225 mg/m2/d

Treatment B:

50.4 Gy with 5-FU CIV 225 mg/m2/d PLUSOxaliplatin 60 mg/m2 weekly x 6cT3/4 or cN+

resectablerectal cancer

N=747

All cases had TME 6-8 weeks later and post-op adjuvant 5-FU chemo as per centre policyPrimary EP was OS

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RESULTS

5-FU CRT5-FU, oxali

CRTp-value

Path CR 16% 16% 0.94

Gr 3-4 toxicityAny

Diarrhea8%4%

24%15%

<0.0001<0.0001

Grade 2-3 neurosensory 0.5% 36% <0.0001

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STUDY COMMENTARY

• This trial sought to improve on outcomes in rectal cancer by adding oxaliplatin to standard 5-FU based CRT

• The trial primary EP was OS which is not yet reported

• This presentation related to the secondary EP of pathologic CR and toxicity

• Surprisingly, these data do not show ANY improvement in rate of pathologic CR when oxaliplatin is added to standard 5-FU based neoadjuvant CRT

• Oxaliplatin added substantial toxicity to treatment

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BOTTOM LINE FOR CANADIAN MEDICAL ONCOLOGISTS

• Standard of care for stage II/III rectal cancer remains 5-FU based neoadjuvant CRT without oxaliplatin.